1. Technical Field
The embodiments described and claimed herein relate generally to restraint devices for vehicles. More specifically, the embodiments described relate to improved track fittings that can withstand higher loads than existing fittings, for safely securing an object to a floor track in a vehicle (train, bus, van, plane, etc.).
2. Background Art
Conventionally, vehicles equipped with passenger seats, wheelchair restraints, or the like, have embedded on their floors channel-shaped tracks with slots into which one or more anchors can be inserted. For example, in wheelchair-accessible vehicles such as a bus, a track is installed onto vehicle floors and walls, and used as an anchoring point to secure standard bus seats, wheelchairs, occupant restraint systems, or securement accessories. Oftentimes, the tracks are installed lengthwise (front to back of vehicle) on the vehicle floor to create a plurality of anchoring points to attach seats. This method of installing the track is very efficient because with a one-track layout on the floor, the seats can be placed at different locations in the bus to meet customer specifications. It is common for bus operators to reconfigure seating and wheelchair configurations periodically and thus, it is important to have a fastening device that allows for quick removal and installation of seats.
One type of track that is commonly used in vehicles is the L track. Each L track has a series of spaced-apart circular slots between which the open upper side of the channel-shaped track narrows. Anchors are designed with lugs extending laterally from the lower part of the anchor. The lugs fit through the slots in the track, and the anchor is moved such that the lugs lie underneath the narrowed portions of the upper side of the channel-shaped track to prevent removal of the anchor from the track. Such devices also include a locking mechanism to lock the lugs underneath the narrowed portions of the track.
Current systems on the market that aim for quick removal and installation of seats onto the track are the commonly-used single and double stud fittings. In buses equipped with L track, these single and double stud fittings are designed to be bolted to the track for semi-permanent installation and have been moderately successful for attachment of seats while retaining a low profile as to size and numerosity of parts. However, due to changes in the industry and upcoming new regulations, these studs may not have sufficient strength to secure the seat to the vehicle floor tracks. The single and double stud fittings have small surface areas when installed into the L track, increasing stress concentration, which reduces the pull-out force of the fitting from the track. For example, school buses can incorporate seat belts which are attached to the attached seat frame rather than the vehicle frame. The added mass of the seated occupants will induce higher loads to the seat frame, which in turn will be transmitted to the stud fitting via the seat legs, and the load further intensified in the event of sudden deceleration. Further, the locking mechanisms of the single and double stud fittings provide for only one index member on each side of the track, resulting in a device that is compact but not one that can provide sufficient shear loads necessary for high mass or force.
Existing technology is also limited by the placement of the stud. Existing fittings place the stud in a location where it must be able to fit in between the narrowing portions of the L-track. Therefore, the maximum diameter of the stud is limited by the width of the narrowing portions of the L-track. This limits the size and overall strength of the fitting.
For these reasons, a stronger stud fitting capable of withstanding these forces while retaining a low profile is needed. An added benefit of having a stronger stud fitting is that it can be used in combination with the double and single studs to be able to attach different seat leg designs as well as minimize the amount of fittings needed to meet strength requirements. The present invention is an improvement over existing technology, which places the stud such that it is located in between the narrowing portions of the L-track. This limits the size and overall strength of the fitting. The fittings embodying the present invention allow the stud to be above the narrowing portions and the stud is supported by a strong beam. This allows the stud to be wider than the narrowed portions of the L-track.